• 제목/요약/키워드: Shore protection

검색결과 76건 처리시간 0.024초

연안 습지식생에 의한 파랑감쇠 특성 (Characteristics of Wave Attenuation with Coastal Wetland Vegetation)

  • 이성대
    • 한국습지학회지
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    • 제18권1호
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    • pp.84-93
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    • 2016
  • 해양과 육지 사이에 있는 연안습지는 연안의 수질을 개선하고 다양한 생물의 자연적인 서식처로 이용될 뿐 아니라 연안침식을 억제하는 기능을 가지고 있다. 연안식생은 외해에서 입사하는 파에너지 또는 폭풍해일을 감소하며 해저 안정화를 통해 습지를 유지하는 기능을 가지고 있다. 식생에 의한 파랑감쇠의 특성을 위해서는 식생과 파랑의 역학적 과정의 검토가 필수적이며 이를 통해 연안과정이나 연안의 동수역학적 특성을 이해할 수 있다. 본 연구에서는 파랑조건 이외에 식생형태에 따른 파랑감쇠 특성을 정량화하기 위해 수리실험을 통해 검토하였으며, 식생모형은 강성식생을 대상으로 규칙파가 작용하는 경우에 대해 파악하였다. 파형경사 ak와 상대수심 kh에 따른 수면위로 돌출된 식생에 대한 파랑감쇠를 검토하기 위하여 수리실험과 수치해석을 수행하였다. 실험결과에 대한 파고감쇠는 Dalrymple et al.(1984)의 파고감쇠식을 통해 식생에 의한 파고전달율, 감쇠율 및 항력계수를 해석하였다. 실험결과 식생에 작용하는 항력계수는 Reynolds수 보다는 Keulegan-Carpenter 수와 상관성이 있고, 파형경사가 증가할수록 파고감쇠율이 증가하고 있음을 확인하였다.

삽목에 의한 갯버들 근계의 토양전단강도 보강효과 (The Effect of Reinforcing Soil Shear Strength by a Root System Developed from Direct Sticking of Salix gracilistyla Miq)

  • 이춘석;임승빈
    • 한국조경학회지
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    • 제31권5호
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    • pp.1-10
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    • 2003
  • The purpose of this study was to verify the shore margin protection effect of a root system developed from direct sticking of Salix gracilistyla Miq., focusing on the reinforcement of soil shear strength. The materials were 20cm long sticks whose average diameter and weight were 7.52mm and 14.58g respectively, and sandy loam(Sand 60.36%, Silt 28%, Clay 11.64%), whose maximum dry weight(${\gamma}$$_{dmax}$) was 1.59gf/㎤ at the water ratio( $W_{opt}$) 13.8%. The direct shearing test(KS F 2343) was applied to cylindric columms(diameter 132mm) of pure soil and two years old root reinforced soil. At each condition of vertical stress, 10N/$ extrm{cm}^2$, 14.41N/$\textrm{cm}^2$ and 18.82 N/$\textrm{cm}^2$, five soil+root columns were sheared. After shear tests, the root area ratio and soil moisture on the shear plane were measured. The results of this research were as follows: 1. The average of root area ratio was 1.86% and the soil moisture 14.67%. 2. Two years old root system was found to increase the soil shear strength of pure soil in terms of Cohesion(C) and Inner friction Angle($\phi$) as follows. 3. The relationship between root area ratio and the increased shear strength can be presented with the following equation, $\Delta$S ≒ 0.33ㆍ TrㆍAs/A $\Delta$S : Increased Shear Strength Tr : Average Tension Strength of Root, Ar/A : Root Area Ratioioage Tension Strength of Root, Ar/A : Root Area Ratio

Estimation of Harbor Responses due to Construction of a New Port in Ulsan Bay

  • Lee, Joong-Woo;Lee, Hoon;Lee, Hak-Sung;Jeon, Min-Su
    • 한국항해항만학회:학술대회논문집
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    • 한국항해항만학회 2004년도 Asia Navigation Conference
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    • pp.217-225
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    • 2004
  • Introduction of wave model, considered the effect of shoaling, refraction, diffraction, partial reflection, bottom friction, breaking at the coastal waters of complex bathymetry, is a very important factor for most coastal engineering design and disaster prevention problems. As waves move from deeper waters to shallow coastal waters, the fundamental wave parameters will change and the wave energy is redistributed along wave crests due to the depth variation, the presence of islands, coastal protection structures, irregularities of the enclosing shore boundaries, and other geological features. Moreover, waves undergo severe change inside the surf zone where wave breaking occurs and in the regions where reflected waves from coastline and structural boundaries interact with the incident waves. Therefore, the application of mild-slope equation model in this field would help for understanding of wave transformation mechanism where many other models could not deal with up to now. The purpose of this study is to form a extended mild-slope equation wave model and make comparison and analysis on variation of harbor responses in the vicinities of Ulsan Harbor and Ulsan New Port, etc. due to construction of New Port in Ulsan Bay. This type of trial might be a milestone for port development in macro scale, where the induced impact analysis in the existing port due to the development could be easily neglected.

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해양경비수요 증대에 따른 해양경비 효율화 방안 (Increasing demand formaritime security measures to streamline the maritime security)

  • 서진석
    • 융합보안논문지
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    • 제14권3_2호
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    • pp.13-21
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    • 2014
  • 국토의 3면이 바다인 반도의 지형을 갖고 있는 우리나라는 자원의 보고인 바다의 중요성을 인식하고, 해양영토 확장 및 권익보호를 위한 해양정책을 추진하는 등 국가해양력 강화를 위해 노력하고 있다. 그러나 해양활동의 무대가 200해리 배타적 경제수역(EEZ)과 대륙붕까지 확장됨에 따라, EEZ가 중첩되는 해역에서의 관할권, 도서영유권, 해양과학조사 및 대륙붕 개발 등을 둘러싸고 인접국과 복잡한 이해관계가 심화되는 등 국제적 협력과 국가간 경쟁이 공존하고 있다. 이러한 때에 해양경찰은 기존의 해양주권수호에서부터 사고예방 중심의 안전관리체계 구축에 이르기까지 우리 바다를 굳건히 지켜왔다. 특히 해상안보, 해양사고, 해상범죄, 해양오염에 있어 날로 증가하는 경비수요에 효율적으로 대응하기 위하여 최선의 노력을 다하고 있다.

공기압을 이용한 전기설비 침수 방지 장치 개발에 관한 연구 (The development for flooding prevention apparatus of electrical equipment using air pressure)

  • 김기현;전현재;이상익;배석명;이재용
    • 한국조명전기설비학회:학술대회논문집
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    • 한국조명전기설비학회 2008년도 춘계학술대회 논문집
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    • pp.281-284
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    • 2008
  • Inundation of substation and ground power equipment breaks out every summer season in low-lying downtown and low-lying shore by localized heavy rain, typhoon and tidal wave. In case inundation excluding the exchanging cost of equipment, it occurs a great economic and social loss owing to recovery time and events of electric shock occur by inundation electrical equipment(Pad-mounted Transformer and Switch). In case of installing the power equipment at flood danger territory, we are necessary to the product development, the product is that water does not come in the inside the power equipment. Product of pressure maintaining are established on the basic frame and sensor operates at the flooding occurrence and is maintained a shutting tightly structure and it is a method. The product which is produced the reliability of the product it confirmed a flooding yes or no from the condition which puts in the water tank and it verified. We estimate that loss cost which is caused by with flooding and the power failure will be diminished if it is addition to advances the reliability evaluation and a security of the flood protection product.

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인공 구조물에 의한 해빈변형 연구 (The Study of the Beach Change into Structures)

  • 김효섭;정병순;오병철
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2004년도 학술발표회
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    • pp.1445-1449
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    • 2004
  • Even though there can be a relative long-term or short-term change of their size in natural beaches due to various changes of sea condition such as the location, weather condition (wind and rain) and sea water flow, the budget of deposits in a specific area is generally regarded to be in a condition of equilibrium in terms of technology. However, as coasts are developed by many different kinds of ways (such as construction of sea walls and estuarine, dredging for gathering the aggregate and shore protection construction for establishing a structure) and sources of silt and gravel from rivers are decreased in balanced beaches, the beaches are in a serious danger of lack of sand and sand sources which are one of the maul elements to consist of them. Many swimming beaches in East Sea are directly exposed by waves generated and transmitted from outer seas. On the other hand, the Song-Do sandy beach which is this study's target area has a great condition for beach development because it locates the deepest place that is relatively shallow in Young-Il Man and there is big energy decrease given to waves from outer seas while the waves are reaching the Song-Do beach. Nevertheless, it is considered that artificial condition changes such as dredging for site extension by POSCO, getting straight of Hyoung-San Gang river flow and extension of Po-Hang harbor caused the sand loss of the beach. Therefore, some recovery plans of Song-Do sandy beach will be presented in this study and they will be compared and examined each other by numerical modeling experiment. After that, the best plan will be recommended.

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e-Navigation 준비를 위한 MSI 서비스 프로토타입 기초 연구 (Basic Study on the MSI service prototype for preparation of e-Navigation era)

  • 오세웅;정민;박진형
    • 한국항해항만학회:학술대회논문집
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    • 한국항해항만학회 2014년도 추계학술대회
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    • pp.42-43
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    • 2014
  • 항해와 기상에 관한 경보/예보 정보인 MSI(Maritime Safety Information)는 e-Navigation의 육상기반 서비스인 MSP(Maritime Service Portfolio)중 하나의 서비스로 포함되었고, 유럽 지역의 다양한 e-Navigation 테스트 베드 프로젝트에서 시험 되는 등 중요한 서비스로 인식되고 있다. 본 연구에서는 e-Navigation 시대에 대비하여 항해 환경에 중요도가 매우 높은 MSI 서비스에 대해 프로토타입 개발 연구를 수행 하였으며, 세부 내용으로, MSI 및 NAVTEX 현황에 대해 분석하였고, NAVTEX 운영에 있어서 제약사항과 개선사항을 정리 하였다. 또한 e-Navigation 정보 표준으로 간주되고 있는 S-100 표준을 기반으로 MSI 서비스 프로토타입 기초 연구를 수행 하였다.

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해안간척지 토양의 생물학적 토성개량에 관한 연구 (제 2 ) -간척지토양에 있어서 생물의 화에 대하여- (Biological improvement of reclaimed tidal land soil (II) -Changes of soil-microbial populations in reclaimed tidal land-)

  • 홍순우;하영칠;이광웅
    • 미생물학회지
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    • 제6권4호
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    • pp.131-140
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    • 1968
  • The soil of the reclaimed tidal land, located in Chogi-ri, Is. Kanghwa, Korea was used in this experiment. The experimented soil samples were collected from 18 sites with its time elapsed after the shore-protection works, soil-depth and the vegetation of saline plants, and at each site samplings were conducted monthly from March through October, 1968, for the purposes of examining the changes of microbial populations for the microbes such as bacteria, actinomycetes and fungi, by using the dilution plate method. The numbers of the microbes in these soils generally showed lower levels comparing with those of other soils. The more time elapsed after the reclamation, the higher numbers of the microbes inhibited the soils. Higher populations were there in the surface soils than in the lower part of the area. The surface soils included comparatively better conditions in aeration and contents of organic matter than in the lower part, and this fact was. same as in general soils. However, not so was this in the case of March, April and October due to the higher soil temperatures in the lows. At the experimental sites where the halophytes such as Salicorniu were grown vigourously, the more densly the plants grew, the higher populations of actinomycetes and fungi were, but not in the case of bacterial population. This means, in this soil with dense Salicornia, it is difficult to obtain good-natured soils in short time without a higher population of bacteria. For the rapid utilization of the land soil, in this view of point, the methods increasing the number of bacteria in the soil are needed as well as the cultivation and harvesting Salicorniu which indicated in the privious paper(Hong, et al., 1969a). According to the results of this experiment, the changes of soil-microbial populations in the reclaimed tidal land soil containing high salinity depend deeply upon the interrelations of many environmental factors such as soil-salinity, soil-components and contents, concentration of organic matters, pH, aeration, and air and soil temperatures, as in the general soils.

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농촌지역 소규모 소택형습지의 유형분류 및 기능평가 연구 (The Type Classification and Function Assessment at Small Palustrine Wetland in Rural Areas)

  • 손진관;김남춘;강방훈
    • 한국환경복원기술학회지
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    • 제13권6호
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    • pp.117-131
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    • 2010
  • This study was conducted to utilize as basic information for the construction of conservation and estimation system for Palustrine wetland, which was badly managed and imprudently reclaimed, through the analysis of distribution characteristics and the estimation of conservation value for sample sites (eight wetlands) in rural area. As the result of wetland type classification, these wetlands was classified by 4 types (Permanent freshwater marshes/pools, ponds, Aquaculture ponds, and Seasonally flooded agricultural land) by Ramsar system, 3 types (Emergent Wetland, Aquatic Bed, and Scrub-Shrub Wetland) by NWI (Cowardin) System, 5 types (Farm Pond Depression, Under-flow wetland, Man-made Pond Depression, Abandoned Paddy Fields Wetland, and Reservoir Shore) by National Wetland's Categorical System, and 3 types (Aquatic Bed Wetland, Emergent Wetland, and Forested Wetland) by Lee (2000) System. These results suggest us developing the new type classification system for small Palustrine wetland in Korean rural areas. The score of function assessment (The Modified RAM) for small Palustrine wetlands was high at the wetlands nearby hills and rice paddy fields, and low at those nearby upper fields, which was mainly affected by land-use and vegetation. The functions as 'Flood/Storm Water Storage', 'Runoff Attenuation', 'Water Quality Protection' were resulted by the structural difference of inflow and outlet. Some functions as 'Wetland size', 'Wetland to immediate watershed ratio', 'Presence of boat traffic', 'Maximum water depth', 'Fetch of water's body' of RAM were not appropriate in evaluation of small wetlands in rural area. Which suggest us developing the new function assessment system for small Palustirne wetland in Korean rural areas.

이층유체에서 부분 장벽에 의한 표면파와 내부파의 분산 (Surface and Internal Waves Scattering by Partial Barriers in a Two-Layer Fluid)

  • 슈레쉬 쿠마;오영민;조원철
    • 한국해안·해양공학회논문집
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    • 제20권1호
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    • pp.25-33
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    • 2008
  • 파랑은 주로 바람에 의해서 발생하여 많은 에너지를 해안으로 전달하며 각종 수리현상을 야기하고 물질의 이송 등에 의하여 연안환경 뿐만 아니라 인간의 활동에도 큰 영향을 미친다. 또한, 해안 구조물과 파랑의 상호작용에 의한 효과를 정확히 예측하는 것은 구조물의 설계 및 거동특성 파악에 매우 중요하다. 본 논문에서는 이층 유체에서 수표면과 저층에 설치되어 있는 얇은 연직벽에 의한 표면파와 내부파의 분산을 선형파 이론을 이용하여 이차원으로 해석하였다. 반사계수를 계산하여 여러 경우에 대하여 효과를 분석한 결과 반사계수는 구조물의 형상과는 별도로 경계층의 위치와 유체간의 밀도차에 크게 영향을 받는 것으로 밝혀졌다.